The features and prognostic factors of 67 cases of Kaposi's sarcoma (KS) associated to the acquired immunodeficiency syndrome (AIDS) diagnosed at the Hospital Clinic, Barcelona, are analyzed. All the patients were male; mean age was 39.7 years, ranging from 22 and 62 years. 64 were homosexuals (95.5%), two were homosexual-drug addicts (3%) and one was drug addict (1.5%). Prevalence of cytomegalovirus and herpes virus infections were 91.1% and 89.5% respectively. In 42 cases (62.7%) KS was the initial AIDS presentation. The most common localization was the skin (89.5%), followed by the digestive tract (52.2%) and the lymph nodes (22.4%). Staging distribution was: 20 patients (29.8%) were in stage I, 11 patients (16.4%) in stage II, 7 patients (10.4%) in stage III, and 29 patients (43.2%) in stage IV. Constitutional symptoms associated to KS were found in 37 patients (55%). Overall 39 patients have already died, and the actuarial survival possibility of these 67 cases was 55% after 12 months. Univariant statistical analysis showed the presence of six variables with prognostic significance (p less than 0.05): staging, symptomatology, total white blood count, total lymphocyte count, T helper lymphocyte count and hemoglobin. Multivariant statistical analysis only chose the staging and symptomatology variables as independent (p less than 0.01 and p less than 0.001, respectively).